import time

time01 = time.time()  #起始时刻
a = ""
for i in range(1000000):
    a += "sxt"

time02 = time.time()   #终止时刻

print("运算时间："+str(time02-time01))


time03 = time.time()   #起始时刻
li = []
for i in range(1000000):
    li.append("sxt")

a = "".join(li)

time04 = time.time()   #终止时刻

print("运算时间："+str(time04-time03))


